Introduction and optimum effectiveness of BMPs, water quality monitoring will be a necessary activity for the Agricultural nutrients, primarily nitrogen (N) rowers in the EAA and phosphorus (P), in drainage water from farms in the Everglades Agricultural Area (EAA) are al- variations in P concentrations occur be- Large variations in P concentrations occur be- leged to be contributing to the eutrophication of seasonally, and within individual tween farms, seasonally, and within individual Lake Okeechobee and undesirable changes in the drainage events on a farm (Izuno et al. 1990a; Water Conservation Areas (WCAs) and the Ever- Bottcher; 1991). Izuno et al. 1991b; and Izuno and Bottcher; 1991). glades National Park (ENP) ecosystems (Florida glades National Park (ENP) ecosystems (Florida Therefore, simply collecting and analyzing a water Department of Administration, 1976; LOTAC , sample occasionally will provide little useful infor- 1986; LOTAC II, 1990; SFWMD, 1990). The ques- nation. A meaningful farm water quality monitor- tion of whose responsibility it is to alleviate the flux ing ogam eue tt comprehensive moni- ing program requires that a comprehensive moni- of nutrients to those protected environments is developed and toring program will need to be developed and presently (1991) being debated. There are many implemented at each farm location. Because the implemented at each farm location. Because the indications that much of the physical and financial characteristics, water management, and physical characteristics, water management, and burden will be placed on the agricultural commu- burden will be placed on the agricultural commu- cultural practices differ among farms, each site nity (SFWMD, 1990). could potentially require a unique program. The Ni n ad P cs in EA fm purpose of this publication is to provide general in- Nitrogen and P concentrations in EAA farm formation to consider when developing a water drainage water are higher than background levels fm on to conir wn opin a ar quality monitoring program for an individual farm. in each of the three ecosystems (Lake Okeechobee, WCAs, ENP), and are therefore considered to be environmental threats. Phosphorus has been iden- Nutrient parameters to monitor tified as the limiting nutrient (SFWMD, 1990). In other words, increasing P concentrations will accel- A water sample can be analyzed for numerous stimulth erat ion ofe ited to a discussion of N and P, with the emphasis growth, while decreasing P concentrations will being on P. Total-N (TN) and Total-P (TP) mea- have the opposite effects, surements account for all N and P, respectively, in organic and inorganic forms, measurable using The high nutrient levels in EAA drainage can be standard chemical analysis procedures. Total-N partially attributed to the high water table organic cannot be measured directly, and is therefore deter- soils of the EAA which are shallow, drained, and mined as the sum of Total Kjeldahl Nitrogen (TKN) subject to biological oxidation and mineralization of (Izuno et al., 1991a) and Nitrate (NO 3 ). Total Dis- both N and P. Fertilizer P applications vary solved Kjeldahl Nitrogen (TDKN) is simply the widely, from zero to several hundred lbs/ac/yr, de- fraction of TKN that passes through a 0.45ym fil- pending on the crop and P available in the soils. ter, separating out the particulate-N. Ammonium Therefore, fertilization practices have a variable (NH 4 ) is another parameter commonly measured impact on P concentrations throughout the EAA. and provides a breakdown of the TKN into inor- Nitrogen fertilizer is rarely used. Rainfall events ganic and organic N. in south Florida are characteristically of high vol- ume and intensity, necessitating drainage to off- Total-P represents all organic and inorganic farm canals. High nutrient concentrations and forms of P, measurable using a standard chemical large drainage volumes translate to high nutrient analysis procedure (Izuno et al., 1991a). Other P loading rates to drainage water receiving areas. parameters commonly analyzed for are Ortho-Phos- phate (PO4), Soluble Reactive Phosphorus (SRP), Attempts to reduce area nutrient loadings and Total Dissolved Phosphorus (TDP). Particulate should logically begin at the farm level. The Sur- P is calculated as the difference between TP and face Water Improvement and Management (SWIM) TDP. Plan (SFWMD, 1990) suggests implementing on- farm Best Management Practices (BMPs) to reduce The current SWIM Plan (SFWMD, 1990) focuses on-farm P concentrations and loadings. After low- on TP. Hence, the minimal analysis of a water ering P concentrations and loadings at the farm sample for south Florida should include TP. How- level, regional Stormwater Treatment Areas (STAs) ever, TP includes particulate forms of P, the would be used to further polish the agricultural amount of which could be greatly influenced by drainage water. To assure the proper management sampling procedures. Hence, it is advisable to also 1
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Introduction and optimum effectiveness of BMPs, water qualitymonitoring will be a necessary activity for the
Agricultural nutrients, primarily nitrogen (N) rowers in the EAAand phosphorus (P), in drainage water from farmsin the Everglades Agricultural Area (EAA) are al- variations in P concentrations occur be-Large variations in P concentrations occur be-leged to be contributing to the eutrophication of seasonally, and within individualtween farms, seasonally, and within individualLake Okeechobee and undesirable changes in the drainage events on a farm (Izuno et al. 1990a;Water Conservation Areas (WCAs) and the Ever- Bottcher; 1991).Izuno et al. 1991b; and Izuno and Bottcher; 1991).glades National Park (ENP) ecosystems (Floridaglades National Park (ENP) ecosystems (Florida Therefore, simply collecting and analyzing a waterDepartment of Administration, 1976; LOTAC , sample occasionally will provide little useful infor-1986; LOTAC II, 1990; SFWMD, 1990). The ques- nation. A meaningful farm water quality monitor-tion of whose responsibility it is to alleviate the flux ing ogam eue tt comprehensive moni-ing program requires that a comprehensive moni-of nutrients to those protected environments is developed andtoring program will need to be developed andpresently (1991) being debated. There are many implemented at each farm location. Because theimplemented at each farm location. Because theindications that much of the physical and financial characteristics, water management, andphysical characteristics, water management, andburden will be placed on the agricultural commu-burden will be placed on the agricultural commu- cultural practices differ among farms, each site
nity (SFWMD, 1990). could potentially require a unique program. The
Ni n ad P cs in EA fm purpose of this publication is to provide general in-Nitrogen and P concentrations in EAA farm formation to consider when developing a water
drainage water are higher than background levels fm on to conir wn opin a arquality monitoring program for an individual farm.in each of the three ecosystems (Lake Okeechobee,
WCAs, ENP), and are therefore considered to beenvironmental threats. Phosphorus has been iden- Nutrient parameters to monitortified as the limiting nutrient (SFWMD, 1990). Inother words, increasing P concentrations will accel- A water sample can be analyzed for numerous
stimulth erat ion ofe ited to a discussion of N and P, with the emphasisgrowth, while decreasing P concentrations will being on P. Total-N (TN) and Total-P (TP) mea-have the opposite effects, surements account for all N and P, respectively, in
organic and inorganic forms, measurable usingThe high nutrient levels in EAA drainage can be standard chemical analysis procedures. Total-N
partially attributed to the high water table organic cannot be measured directly, and is therefore deter-soils of the EAA which are shallow, drained, and mined as the sum of Total Kjeldahl Nitrogen (TKN)subject to biological oxidation and mineralization of (Izuno et al., 1991a) and Nitrate (NO3). Total Dis-both N and P. Fertilizer P applications vary solved Kjeldahl Nitrogen (TDKN) is simply thewidely, from zero to several hundred lbs/ac/yr, de- fraction of TKN that passes through a 0.45ym fil-pending on the crop and P available in the soils. ter, separating out the particulate-N. AmmoniumTherefore, fertilization practices have a variable (NH4) is another parameter commonly measuredimpact on P concentrations throughout the EAA. and provides a breakdown of the TKN into inor-Nitrogen fertilizer is rarely used. Rainfall events ganic and organic N.in south Florida are characteristically of high vol-ume and intensity, necessitating drainage to off- Total-P represents all organic and inorganicfarm canals. High nutrient concentrations and forms of P, measurable using a standard chemicallarge drainage volumes translate to high nutrient analysis procedure (Izuno et al., 1991a). Other Ploading rates to drainage water receiving areas. parameters commonly analyzed for are Ortho-Phos-
phate (PO4), Soluble Reactive Phosphorus (SRP),Attempts to reduce area nutrient loadings and Total Dissolved Phosphorus (TDP). Particulate
should logically begin at the farm level. The Sur- P is calculated as the difference between TP andface Water Improvement and Management (SWIM) TDP.Plan (SFWMD, 1990) suggests implementing on-farm Best Management Practices (BMPs) to reduce The current SWIM Plan (SFWMD, 1990) focuseson-farm P concentrations and loadings. After low- on TP. Hence, the minimal analysis of a waterering P concentrations and loadings at the farm sample for south Florida should include TP. How-level, regional Stormwater Treatment Areas (STAs) ever, TP includes particulate forms of P, thewould be used to further polish the agricultural amount of which could be greatly influenced bydrainage water. To assure the proper management sampling procedures. Hence, it is advisable to also
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